Zou Shiming's learning curve is definitely getting shorter.

China's two-time Olympic gold medalist demonstrated as much on Sunday by following an old boxing axiom to the letter: when you get an opponent in deep water, you have to try to drown him.

In just his third pro fight, Zou had Juan Toscano gasping and grasping in their featured flyweight prelim on Top Rank's 'Clash in Cotai' in Macao, but despite constant pressure and crisp, accurate punching, Zou could not make the granite-chinned Mexican kiss the canvas.

Still, en route to winning all six rounds on every scorecard, the pride of China showed huge improvement over his last outing. He landed several murderous combinations, and on three occasions had Toscano reeling and ready to go. But the 27-year-old native of Ensenada proved again and again he could take a licking and keep on ticking.

"As a rookie professional with just three fights, I would rate my performance an eight out of 10," Zou said through an interpreter. "But as a fighter who wants one day to be a world champion, I would rate this fight as just a five because I did not get a knockout.

"I tried hard for the KO but my opponent had a very strong chin and he could really take a punch. But I think I showed my power is improving and I am confident that the knockouts will come."

The biggest improvement in Zou is a growing confidence in throwing punches in bunches rather than firing single potshots. Against Toscano, who was unbeaten (4-0) coming in, Zou stayed in the pocket and sat down on his punches, slamming powerful straight rights behind a razor jab that slashed deep cuts on the Mexican's face.

"My improvement was the result of being in Manny Pacquiao's camp with (trainer) Freddie Roach. It is an honor to have the opportunity to learn from the best fighter and the best trainer in the world," said Zou. "I hope I can continue to improve and give all of China a reason to be proud of me."

Besides more power, Zou showcased a much better command of cutting off the ring. Every time his opponent tried to circle out of the corner, Zou took a step or two sideways into the punching lane to keep him trapped.

"His movement is something we are really focusing on, especially laterally," said Roach. "In the amateurs it is easy to fall into the habit of always stepping straight back after a punch, but in the pros you have to slip and move, cut the other guy's escape route."

Zou's impressive win capped a perfect day for the quartet of Chinese fighters on the undercard of Pacquiao vs Brandon Rios.

In other actions involving Chinese fighters:

With Roach working his corner, Ik Yang of Dalian improved to 13-0 with a majority decision over Indonesia's Hero Tito in their six-round super lightweight match.

Macao's Ng Kouk Kun went to 2-0 with a stylish four-round super welterweight win over You-Jie Zeng of Thailand. Kouk, a sharp puncher with both fists, is shaping up as a real crowd pleaser.

Popular Hong Kong bantamweight Rex Tso showed why he has rock star appeal by notching a quick knockout of Thailand's Susu Sithjadeang. Now 8-0-2 with 5 KOs, Tso adroitly combined slick footwork with devastating punching power.

murraygreig@chinadaily.com.cn